Manufacture of carbon black



June 30, 1931. G, c LEW|5 MANUFACTURE OF CARBON BLACK Filed Dec. 51, 1927 INVENTOR W7 A ATTOENEYJ CL/ Patented June 30, 1931 UNITED STATES PATENT OFFICE GmBB'E CHARLES LEWIS, OF NEW DORP, NEW YORK; ASSIGNOR '10 GAR- BON' COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE unuurncrunn or cannon BLACK Application filed December 31, 1927. Serial No. 243,899.

'As is well known, the burning of natural gas or other hydrocarbons with the flame impinging on a channel or other metal surface is employed commercially for the production of carbon black, but the yield is very small in comparison with the theoretical maximum of the carbon in chemical combination in the gas being burned. In spite of the low yield this method is still employed to a very large extent, because no known method produces a carbon black having exactly the same combination of characteristics such as fineness, softness, purity, color, dispersibility, etc., for which there is a large demand.

The main object of my invention is to secure an increased yield of carbon black from the hydrocarbon employed, and without changing to any appreciable or objectionable degree the highly desirable characteristics of the product which result from the impinging of the flame on the collecting surace.

I have discovered that the deposition of the carbon from a flamewhere there is incomplete combustion is atfected by the frequency of the light waves playing upon the flame or depositmg surface, and that an increase in the amount of short length light waves materially increases the separation and deposition of the incandescent carbon and an increase in the yield of carbon black obtained from the burning of a given amount of hydrocarbon. The luminosity of the flame is in part dependent upon the incandescent carbon in the flame, and the light rays emitted therefrom are very largely at the red or yellow low frequency end of the spectrum. Thus the light rays emitted from one flame include a very small and practically unmeasurable amount of the short length waves or ultra violet light rays at or beyond the opposite end of the visible spectrum.

I have discovered that by positioning a source of light adjacent to the flame or the depositing surface of such a character that it emits'a comparatively large amount of the ultra violet or other short length light waves, a larger proportion of the carbon in the material burned in the flame will separate out and collect on the depositing surface. Although the auxiliary source of light which I employ may include light rays of the entire spectrum, it is not essential that there be emplo ed other than the high frequency rays. Xlthough the rays which appear to have the most desirable efi'ect are those within the range commonly referred to as ultra violet, I desire to include in the term short length the rays at the violet end of the spectrum, the ultra violet rays, and those of shorter-wave length than the ultra violet, such for instance as the Roentgen or X-ray. Light rays of a wave length greater than 302 mu have little or no effect, and by the term short wave I include only those light rays which,have a wave length of 302 mu or less.

Any suitable apparatus may be employed for the production of the desired high frequency or short length light rays, but no apparatus is suitable for the purpose unless it has a substantial proportion of emitted rays below 302 mu. Merely as an example I may mention a mercury vapor lamp of the quartz tube type. This should be so mounted that the light rays may impinge on both the flame and on the depositing surface. It is known that a depositlng surface of iron appears to have certain catalytic effect in securing a larger deposition of carbon black than can be obtained with certain other materials, and it is possible that the short length light waves in acting upon the metal surface of the depositing plate increase the catalytic action of the latter and thereby increase the deposition of carbon black. 'It is also possible that theincreased deposition is due primarily to the action of the light rays on the incandescent carbon particles in the flame. It is probably due to a combination of these effects, but exact data on this point 1 are difficult to obtain. The source of short length light waves shouldbe so positioned that it does not become coated with any \depositions'of carbon which would interfere with the emission of the light rays and also so positioned that it is not objectionably affected by the high temperature existing in grammatically an apparatus for carrying out my invention.

The drawing shows a pair of iron plates or channels 10 against which the flames 11 from burners 12 may play. These channels and their relationship to the burners may be that commonly employed in the industry, and suitable means are used for effectin the movement of the channels back and forth through the flame with brushes or other fieafis to scrap offthe deposited carbon In carrying out my invention I employ a source of short wave length rays such as a tube 13. In order to get the maximum effect this is positioned between two adjacent burners or rows of burners, and beneath the channels 10 so that the ra s therefrom may play on or bombard the ames and the depositing surfaces upon opposite sides thereof. The tube 13 being below the burners is somewhat away from the heat of the latter, and being below and between the channels does not become coated with any deposited carbon.

-I find that by means of my invention I am able to very materially increase the amount of carbon black which would otherwise be produced from a given hydrocarbon. The hydrocarbon may be natural gas, or it may be any other suitable material adapted for burning to produce carbon black. Although the invention is primarily useful for increasing the production of carbon black, it also may be employed for increasing the yield of lamp black where no depositing plates are employed. Ineach case the incomplete combustion of the hydrocarbon results in the production of free carbon, and the ultra violet rays increase the yield of the unburned or separated carbon which may be collected as the desired product.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. The method of producing carbonaceous deposits from a flame, consistin in subjectingthe flame to the action of lig t rays from a source of light emitting a substantial amount of light waves of shorter length than those forming the main portion ofthe light from said flame.

2. The method of producing carbonaceous deposits such as carbon black or lamp black from a flame in which incomplete combustion is effected, said method consisting in bombarding the flame with ultra violet rays.

4. The method of producing carbonaeous deposits which consists in effecting incomplete combustion in a flame and subjecting the flame to ultra violet rays.

5. The method of producing carbon black which consists in cooling a flame to effect a deposition on the cooling medium and delivering light rays of short wave length to the flame.

6. The method of producing carbon black which consists in cooling a flame to effect a deposition on the cooling medium and delivering light rays having a wave length below 302 mu to the surface of the cooling medium.

7. The method of producin carbon black which consists in cooling a ame to effect a deposition on the cooling medium and delivering ultra violet rays to the flame.

8. The method of producin carbon black which consists in cooling a ame to effect a deposition on the cooling medium and delivering ultra violet rays to the surface of the cooling medium.

9. The method of roducing carbonaceous deposits which consists in-playing a flame and light rays of short wave length on a metal surface at the same point.

10. The method of producing carbonaceous deposits which consists in playing a flame andlight rays of short wave length on a metal surface at the same point, and continuously movin the surface to bring fresh parts thereof into action.

11. The method of increasing the yield of carbon black produced by the action of a as flame on a movin iron surface, which 1ncludes the step of ombarding the iron surface with ultra violet light.

12. The method of increasing the yield of carbon black produced by the actionof a gas flame on a moving flame, which includes the step of bombarding the flame with ultra violet light.

13. The method of increasing the yield of carbon black produced by the action of a. gas flame on a moving iron surface, which includes the step of bombarding the iron surface and flame with ultra violet light.

14. An a paratus for producing carbon black inclu 'ng a burner and a source of ultra violet rays disposed adjacent thereto.

15. An a paratus for producing carbon black inclu ing a depositing surface, a burner so positioned that the flame therefrom plays on said surface, and means for delivering light rays of short wave length to said v ame. I

16. An apparatus for producing carbon black including a depositing surface, aburner so positioned that the flame therefrom Y plays on said surface, and means for delivering light rays of short wave length to said 5 surface.

17. An a paratus for producing carbon black inclu ing a depositing surface, a burner so positioned that the flame therefrom plays on said surface, and means for delivering ultra violet rays to said flame. 7

18. An 8. paratus for producing carbon black inclu ing a depositing surface, a burner so positioned that the flame therefrom plays on said surface, and means for delivering ultra violet rays to said surface.

Signed at New York in the county of New York and State of New York this 21st day of December A. D. 1927.

GEORGE CHARLES LEWIS. 

